It used boots but I’m still doing lots of research this cars are 25+ years old. I don’t really need lots of parts just the shocks look weird to me not sure they are stock. Here’s pictures I still need to clean it up then I can make alignment adjustments
The front side also has a little more slack on the springs on the right side
Yea ,Mugen is a top well known contender an is an expensive racing platform ,what parts I seen ,old & new ,are expensive ,an
In fact ,someone on ebay has your mbx4 brand new never built kit for a $ 1000 bucks!..

I think that I would just find a new set of shocks ,or find a rebuild kit for yours ,o rings do rot an go bad ,I'm also seeing
Conflicting shock #'s on that manual ,but I am also seeing a lot of those mbx4 parts on ebay ,but some are pricey!
Mugen tends to use the same MBX letters on everything ,it can be confusing on what model they are referring too ,check
Out this shock housing kit ,they just say MBX ,but there is a part # ,but does not match yours!..

https://www.ebay.com/itm/183619462265?epid=20026909287&hash=item2ac092a479:g:NgkAAOSwgotcLo8y